How to plant a rose-perennial combo
The principles for planting these containers are the same; only the plant combinations change.
Choose a pot that’s 18 to 24 inches in diameter and at least as deep. Steeb favors thick-walled plastic ones, which hold moisture better than terra-cotta, provide good insulation against heat and cold, and weigh less than terra-cotta, ceramic, or cement. If you buy containers without drain holes, drill two or three 1-inch holes in the bottom of the container.
Also buy a bag of rich, fast-draining potting soil. Since potting soil quality varies so much from brand to brand, and brands vary from state to state, ask your nursery for a recommendation. If they say they’re all the same, find a better nursery.